Rotary regenerator seal construction



oct. 25, 1966 s. K. CHEN ETAL 3,280,895

ROTARY REGENERATOR SEAL CONSTRUCTION Filed Sept. 10, 1964 United States Patent O 3 280,895 ROTARY REGENERATOR SEAL CONSTRUCTION Simon K. Chen, Park Forest, and Walter H. Page, Elmhurst, Ill., assignors to International Harvester Company, Chicago, Ill., a corporation of New Jersey Filed Sept. 10, 1964, Ser. No. 395,425 4 Claims. (Cl. 165-9) This invention relates to a stationary sealing `shoe construction for a rotary regenerator. More in particular this invention relates to a sealing shoe construction for a rotary regenerator whereby the shoe under thermal influence changes its contour corresponding to dimensional changes in the rotor occurring under thermal infiuence.

It is well known that under the influence of temperature changes the contour of a cross-section of a regenerator rotor changes due to thermal gradient. Sometimes this phenomena is referred to as bowing or heat warping. Since a given portion of the rotor matrix undergoes widespan temperature changes during each revolution of operation it will be appreciated that thermal gradients deform the matrix such that excessive leakage occurs between the sealing shoes and the rotor. It is a prime object of the present invention to provide a sealing shoe for a rotary regenerator which changes its contour under the influence of heat corresponding to changes in the contour of the rotor whereby the leakage of gas through the seal is eliminated or minimized.

Another important object of the invention is to provide a sealing shoe for a rotary regenerator wherein the clearance of the gas seal is maintained at substantially a constant irrespective of bowing of the rotor under the infiuence of temperature changes.

Still another object of the present invention is to provide a sealing shoe for a rotary regenerator according to the preceding objects at low cost.

These and other desirable objects inherent in and encompassed by the invention will become more app-arent from the ensuing description of a preferred embodiment, the appended claims and the annexed drawing wherein:

FIGURE l is an end View of a rotary heat exchanger with the casing and plenums in phantom lines illustrating a heat exchanger rotor and a pair of gas sealing shoes in operative relation thereto;

FIGURE 2 is a cross-sectional view, partly broken away, of the regenerator rotor and one sealing shoe taken on line 2-2 of FIGURE l, wherein the matrix of the rotor and the shoe are at ambient temperature;

FIGURE 3 illustrates, exaggeratedly for clarity, the arrangement of FIGURE 2 when the matrix of the rotor and the shoe are at elevated temperature; and

FIGURE 4 is a perspective view, partly broken away, of a portion `of one sealing shoe with rotor removed showing construction details thereof.

Referring to the drawing the numeral in FIGURE l indicates generally a conventional rotary regenerator having the improved sealing shoes 11 and 12 as shown. The regenerator 10 is provided with a conventional rotor 13 disposed in a conventional housing with plenums indicated generally at 14. The sealing shoes 11 and 12 are connected together by a wall 15 forming a hot g-as plenum with hot gas inlet shown in dotted lines at 17 and cold air plenum with cold air inlet 16 as is known conventionally. The sealing shoes 11 and 12 are identical in construction and therefore only the shoe 11 will be described in detail.

Referring to FIGURES 1, 2 and 4 the sealing shoe 11 is arcuately shaped and includes segmented shaped end elements or plates 18 and 19 in parallel spaced relation as indicated. Connected to the end plates 18 and 19 in rigid relation is an inner bimetal member 20 and an outer 31,280,895 Patented Oct. 25, 1966 bimetal member 21 forming the sealing shoe 11 through which the rotor 13 moves. It will be apparent that a radial plane passing through the rotor 13, such as shown in FIGURE 2, shows that the matrix, 13a of the rotor 13 is of rectangular cross-section. Likewise from FIGURE 2 it will be apparent that the same radial plan'e indicates that the radial cross-section of the sealing shoe 11 is also rectangular conforming to the cross-sectional configuration of the matrix 13a. It should be understood that small clearances exist between the sealing shoe 11 and the matrix 13a to allow rotary movement of the rotor 13 about its -axis of rotation 22. The bimetal members 20 and 21, the unique and novel feature of this invention, will now be described.

The bimetal member 20 comprises two plates 23 and 24, having different coefiicients of thermal expansion welded together in a unitary structure. It will thus be apparent that if the coefiicient expansion of plate 24 is greater than the coefiicient of expansion of plate 23, then upon elevating the temperature the bimetal member 20 will distort, flex or bow as indicated at 20 in FIGURE 3. Since the bimetal member 21 is constructed similar to member 20 it will be apparent that if the temperature of the shoe 11 of FIGURE 2 is elevated the members 20 and 21 will bow such that shoe 11 will approach a configuration shown at 11 in FIGURE 3.

From the foregoing it will be apparent that if the materials from which bimetal plates 23, 24, 25 and 26 are carefully chosen to match the characteristics of the matrix 13a of the rotor 13, the sealing shoe 11 will bow in magnitude, under influence of temperature change according to known physical properties. For example, in FIGURE 2, if in shoe 11 the plates 24 and 26 are made from AISI No. 347 stainless steel and plates 23 and 25 are made from AISI No. 410 stainless steel, the shoe 11 will bow under the influence of a rise in temperature approximately in conformance with a rotor 13 wherein the matrix 13a of the rotor 13 comprises elements constructed from AISI No. 347 stainless steel. Thus the clearance between the shoe 11 and the rotor 13 are not only maintained at a minimal value but such value is substantially constant throughout the operating temperature range.

Having thus described an embodiment of the invention, it can now be seen that the objects of the invention have been fully achieved and it must be understood that changes and modifications may be made which do not depart from the spirit of the invention as disclosed nor from the scope thereof as defined in the appended claims.

What is claimed is:

1. A rotary regenerator having a rotor including a matrix positioned in heat exchange relation, la gas sealing shoe disposed about said rotor in operative relation, said shoe comprising an inner bimetal member and an outer bimetal member disposed in radial spaced relation, a first segmental shaped end element secured to one end portion of said members in rigid relation, a second segmental shaped end element positioned in parallel spaced relation with respect to said first end element and secured to the other end positions of said members in rigid relation, each of said bimetal members consisting of an outer first plate having a first coefficient of thermal expansion secured rigidly in back-toback relation to an inner second plate having a second coefiicient of the thermal expansion, said members being adapted to flex in response to a temperature change corresponding to a distortion of said matrix responsive to said temperature change whereby the gas seal between said shoe and said rotor remains substantially unaffected throughout the operating temperature range of said regenerator.

2. A sealing shoe for a rotary regenerator according to claim 1 wherein the coefficient of thermal expansion of said rst plate of said bimetal members is greater than the coefficient of thermal expansion of said second plate of said bimetal members.

3. A sealing shoe for a rotary regenerator according to .claim 1 wherein said rst plate of said bimetal members consists of AISI No. 347 stainless steel and said second plate of said bimetal member consists of AISI No. 410 stainless steel.

4. A gas sealing shoe in a rotary regenerator comprising a pair of radially spaced-apart bimetal members in 10 operative gas sealing relation with respect to the rotor of said regenerator, said bimetal members being capable of flexing under the inuence of temperature changes Within a predetermined temperature range to a magnitude corresponding to the magnitude of bowing of said rotor under the influence of said temperature changes whereby the gas sealing efficiency of said shoe remains substantially unchanged throughout said temperature range.

References Cited by the Examiner UNITED STATES PATENTS 2,888,248 5/1959 Bubniak et al. 165-9 3,095,036 6/1963 Teufel 16S-9 3,180,402 4/l965 Moffat 165-9 ROBERT A. OLEARY, Primary Examiner.

A. W. DAVIS, Assistant Examiner. 

4. A GAS SEALING SHOE IN A ROTARY REGENERATOR COMPRISING A PAIR OF RADIALLY SPACED-APART BIMETAL MEMBERS IN OPERATIVE GAS SEALING RELATION WITH RESPECT TO THE ROTOR OF SAID REGENERATOR, SAID BIMETAL MEMBERS BEING CAPABLE OF FLEXING UNDER THE INFLUENCE OF TEMPERATURE CHANGES WITHIN A PREDETERMINED TEMPERATURE RANGE TO A MAGNITUDE CORRESPONDING TO THE MAGNITUDE OF BOWING OF SAID ROTOR UNDER THE INFLUENCE OF SAID TEMPERATURE CHANGES WHEREBY THE GAS SEALING EFFICIENTY OF SAID SHOE REMAINS SUBSTANTIALLY UNCHANGED THROUGHOUT SAID TEMPERATURE RANGE. 